Effect of fennel essential oil on performance, serum biochemistry, immunity, ileum morphology and microbial population, and meat quality of broiler chickens fed corn or wheat-based diet

1. The effect of Foeniculi aetheroleum essential oil (EO) on growth performance, nutrient utilisation, serum biochemistry, immune response, ileum morphology, microbial population and meat quality of broiler chickens fed a corn- or wheat-based diet were determined.2. A total of 360 broiler chickens were arranged in a 2 × 2 factorial assay in a completely randomised design with six replicates and 15 birds per experimental unit. Birds were fed corn- or wheat-based diets supplemented with (200 mg/kg) or without fennel EO.3. Birds fed wheat-based diets had lower BWG and FCR during grower period and lower FI during finisher period as compared to those fed corn-based diet (P < 0.05) whereas addition of fennel EO decreased chickens BWG during finisher period and EPEF, both in wheat or in corn-based diets. Dietary treatments had no effect on serum glucose, triglyceride, cholesterol, LDL-cholesterol, AST, ALT, ALP, and MDA concentrations (P < 0.05).4. Antibody titres against avian influenza and sheep red blood cell antibody titres, crude protein and crude fat utilisation, villus height, crypt depth and epithelium thickness were not influenced by dietary treatments (P > 0.05). Inclusion of Fennel EO to the corn-based diet resulted in greater villus width and villus surface area while it reduced lamina propria thickness (P < 0.05). Fennel EO reduced ileal E. coli and Lactobacillus spp. populations (P < 0.05). Dietary treatments had no significant effect on meat pH, cooking loss, drip loss, crude protein, crude fat content and cholesterol concentration of breast and thigh meat, total phenolic and MDA concentrations, and breast meat sensory parameters (P > 0.05).5. These results showed that addition of fennel EO to wheat-based diets had a negative effect on chicken growth performance variables and decreased gut E. coli populations. However, immunity, meat quality and nutrient utilisation were not affected by dietary treatments.

Evaluation of Antimicrobial Interventions against E. coli O157:H7 on the Surface of Raw Beef to Reduce Bacterial Translocation during Blade Tenderization

The US Department of Agriculture, Food Safety Inspection Service (USDA-FSIS) considers mechanically-tenderized beef as “non-intact” and a food safety concern because of the potential for translocation of surface Escherichia coli O157:H7 into the interior of the meat that may be cooked “rare or medium-rare” and consumed. We evaluated 14 potential spray interventions on E. coli O157:H7-inoculated lean beef wafers (~10⁶ CFU/cm², n = 896) passing through a spray system (18 s dwell time, ~40 pounds per square inch, PSI) integrated into the front end of a Ross TC-700MC tenderizer. Inoculated and processed beef wafers were stomached with D/E neutralizing broth and plated immediately, or were held in refrigerated storage for 1-, 7-, or 14-days prior to microbial enumeration. Seven antimicrobials that showed better performance in preliminary screening on beef wafers were selected for further testing on beef subprimals in conjunction with blade tenderization. Boneless top sirloin beef subprimals were inoculated at ~2 × 10⁴ CFU/cm² with a four-strain cocktail of E. coli O157:H7 and passed once, lean side up, through an integrated spray system and blade tenderizer. Core samples obtained from each subprimal were examined for the presence/absence of E. coli O157:H7. The absence of E. coli O157:H7 in core samples correlated with the ability of the antimicrobials to reduce bacterial levels on the surface of beef prior to blade tenderization.

An assay for determining the susceptibility of Salmonella isolates to commercial and household biocides

Poultry and meat products contaminated with Salmonella enterica are a major cause of foodborne illness in the United States. The food industries use a wide variety of antimicrobial interventions to reduce bacterial contamination. However, little is known about Salmonella susceptibility to these compounds and some studies have shown a concerning link between biocide resistance and antibiotic resistance. To investigate this, a 96 well panel of 17 common household and commercially used biocides was designed to determine the minimum inhibitory concentrations (MIC) of these compounds for Salmonella. The panel contained two-fold serial dilutions of chemicals including Dodecyltrimethylammonium chloride (DC), Benzalkonium chloride (BKC), Cetylpyridinium chloride (CPC), Hexadecyltrimethylammonium bromide (HB), Hexadecyltrimethylammonium chloride (HC), Acetic acid (AA), Lactic acid (LA), Citric acid (CA), Peroxyacetic acid (PXA), Acidified sodium chlorite (ASC), Sodium hypochlorite (SHB), 1,3 dibromo, 5,5 dimethylhydantoin (DBH), Chlorhexidine (CHX), Sodium metasilicate (SM), Trisodium phosphate (TSP), Arsenite (ARI), and Arsenate (ARA). The assay was used to test the susceptibility of 88 multidrug resistant (MDR) Salmonella isolates from animal sources. Bacteria are defined as multidrug resistant (MDR) if it exhibited non-susceptibility to at least one agent in three or more antimicrobial categories. The concentration of biocide at which ≥50% of the isolates could not grow was designated as the minimum inhibitory concentration or MIC50 and was used as the breakpoint in this study. The MIC50 (μg ml-1) for the tested MDR Salmonella was 256 for DC, 40 for BKC, 80 for CPC. HB and HC, 1,640 for AA, 5664 for LA, 3,156 for CA, 880 for PXA, 320 for ASC, 3.0 for CHX, 1,248 for DBH, 3,152 (6%) for SHB, 60,320 for SM, 37,712 for TSP, 56 for ARI and 832 for ARA. A few isolates were not susceptible at the MIC50 breakpoint to some chemicals indicating possible resistance. Isolates with MICs of two 2-fold dilutions above the MIC50 were considered resistant. Biocides for which resistant isolates were detected included CPC (n = 1 isolate), HB (1), CA (18), ASC (7), CHX (22), ARA (16), and ARI (4). There was no correlation detected between the biocide susceptibility of Salmonella isolates and antibiotic resistance. This assay can determine the MICs of bacteria to 17 biocides in a single test and will be useful in evaluating the efficacy of biocides and to detect the development of resistance to them.

Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age

We evaluated the effect of broiler age and aging process on the meat characteristics of breast fillets from female free-range broilers slaughtered at 12 weeks of age (Wk12) and 70 weeks of age (Wk70). We used breast meat from female ISA Label (n = 60) broilers. Ten samples of each broiler age were aged in an incubator (2°C ± 0.5°C) for 3 and 7 days. Ten samples for each broiler age were analysed 4 h post-slaughter (Control group). Compared with breast meat from Wk12, breast meat from Wk70 showed higher shear force (30.52 N vs 27.19; P = 0.0322) and total collagen (4.33 g/kg vs 3.77 g/kg; P = 0.0149), which were reduced during aging to 15.49 N and 3.92 mg/100 g, respectively. The aging process did not affect the lipid oxidation of breast meat from Wk70. After aging for 3 days, breast meat from Wk70 had similar protein and fat contents to those of meat from Wk12 (21.29% and 1.04%, on average, respectively). Breast meat from Wk70 also showed lower concentrations of docosahexaenoic (0.32% vs 0.65%; P < 0.0001) and eicosapentaenoic (0.01% vs 0.12%; P < 0.0001) fatty acids than meat from Wk12. The use of free-range hen meat is beneficial to the industry because of the lower storage and cooking losses, which may influence the final yield, besides its lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to promote the tenderisation of meat from free-range broiler hens.

Trends in microbial control techniques for poultry products

Fresh poultry meat and poultry products are highly perishable foods and high potential sources of human infection due to the presence of several foodborne pathogens. Focusing on the microbial control of poultry products, the food industry generally implements numerous preventive measures based on the Hazard Analysis and Critical Control Points (HACCP) food safety management system certification together with technological steps, such as refrigeration coupled to modified atmosphere packaging that are able to control identified potential microbial hazards during food processing. However, in recent years, to meet the demand of consumers for minimally processed, high-quality, and additive-free foods, technologies are emerging associated with nonthermal microbial inactivation, such as high hydrostatic pressure, irradiation, and natural alternatives, such as biopreservation or the incorporation of natural preservatives in packaging materials. These technologies are discussed throughout this article, emphasizing their pros and cons regarding the control of poultry microbiota and their effects on poultry sensory properties. The discussion for each of the preservation techniques mentioned will be provided with as much detail as the data and studies provided in the literature for poultry meat and products allow. These new approaches, on their own, have proved to be effective against a wide range of microorganisms in poultry meat. However, since some of these emergent technologies still do not have full consumer's acceptability and, taking into consideration the hurdle technology concept for poultry processing, it is suggested that they will be used as combined treatments or, more frequently, in combination with modified atmosphere packaging.